Soy sauce is generally divided into two groups: fermented soy sauce and non-fermented soy sauce. DD. Fukushima, "Soy Proteins for Foods Centering Around Soy Sauce and Tofu", J. Am. Oil Chemists' Soc., March 1981, pp. 346-354. Fermented soy sauce is produced by slowly fermenting a mixture of proteins and carbohydrates. This slow fermentation produces a flavor and aroma characteristic of fermented soy products. Non-fermented soy sauce is produced by rapid hydrolysis of soy proteins. Such a product does not possess the flavor and aroma of fermented products, but is made by a rapid and efficient process and has become a popular flavoring material.
Efforts to improve non-fermented soy sauce have led to the development of non-traditional fermented soy sauces. These non-traditional fermented soy sauces are generally made by hydrolyzing raw soybeans followed by fermentation of the hydrolyzate. For example, U.S. Pat. No. 4,587,127 (Akao, et al.) discloses a process for producing a liquid seasoning comprising allowing a hydrolyzate of soy sauce materials, in a liquid state at a pH of 4.0 to 9.0, to contact immobilized cells of soy sauce lactic acid bacteria for 30 minutes or more to obtain a lactic fermentation mixture which is then subjected to fermentation by a soy sauce yeast. While a fermented flavor note thus results, a need exists for a more efficient process that does not involve fermentation and its attendant limitations.
One of the characteristic reactions of the components of hydrolyzates of soy sauce materials, i.e., proteins and carbohydrates, is the "Maillard reaction". This reaction produces an increase in the product's absorption of visible radiation, i.e., "browning" of the products. For example, U.S. Patent No. 3,879,561 (Smith, et al.) describes dry condiment paraticulates produced by simultaneously drying and reacing under sub-aatmospheric pressure and at an elevated temperature aan aqueous medium which contains amino acids and/or protein hydrolyzates in conjunction with starch hydrolyzates as major dry components. The Maillard reaction is not restricted to soy sauces, and has been used for maple flavors, as described in U.S. Pat. No. 2,446,478 (Kremers), and chocolate flavor, as described in U.S. Pat. No. 2,835,592 (Rusoff). In the preparation of these flavors, the components are reacted in a substantially anhydrous molten state to provide the characteristic flavors.
A need still exits in the art for a means of producing an edible composition which possesses a fermented soy sauce character, but which can be efficiently produced.